Net-zero energy ready building codes and their steps
Net-zero energy ready code tiers are a stepped scale in the National Building Code that lets a province raise the minimum energy performance of new houses and small buildings in stages. The top tier describes a building so efficient that on-site renewable energy could cover its annual needs, although the building does not have to include that equipment.
What are the energy tiers in the building code?
The 2020 edition of the National Building Code added a tiered structure to its energy provisions for houses and small buildings. Tier 1 is the baseline and roughly matches the older requirement. Each higher tier asks for a better result, and the top of the scale, Tier 5, is the net-zero energy ready level. Our overview of building code energy rules in Canada shows where these provisions sit in the wider code system.
The point of the steps is policy flexibility. A province can adopt Tier 2 now, signal Tier 3 for a later date and keep climbing, which gives builders time to learn new methods and suppliers time to stock the products.
What does net-zero energy ready mean?
It describes a building designed and built so that its energy use is low enough to be matched by renewable generation, usually rooftop solar, over a year. The solar panels themselves are not part of the code requirement. A net-zero ready house is the efficient shell, tight envelope and efficient equipment that make a later net zero home possible.
Net zero energy is different from net zero emissions. An energy ready home that heats with natural gas still produces emissions, and a home heated by an electric cold-climate heat pump on a clean grid produces far fewer. Some governments pair the tiers with limits on carbon, but those rules vary and should be checked locally.
How are tiers met in practice?
Houses can follow a prescriptive route, where the code lists the insulation, window and equipment levels for each tier, or a performance route that proves the result through energy modelling. The higher tiers are harder to hit by simple prescriptive packages, so modelling by a certified energy advisor is common at those levels.
The ingredients tend to be familiar ones.
- More insulation and better windows than the baseline.
- A tighter envelope, checked with an air tightness test.
- Mechanical ventilation with heat recovery, such as a heat recovery ventilator.
- Efficient heating and water heating equipment, often a heat pump.
Several ways of reaching the same score exist, and the cheapest mix depends on the house and the region.
Which tier applies in your province?
The tier that is legally required is a provincial or territorial decision, and some municipalities offer voluntary higher tiers or incentives for builders who go beyond the minimum. Governments have talked about moving toward net-zero energy ready codes around 2030, but the pace differs from place to place and the plans can change.
To find what applies, check the provincial ministry that administers the building code, ask the municipal building department which edition and tier your permit falls under, and confirm with your builder. Do not rely on a general article, including this one, for the legal minimum on a specific project.
Is a high tier worth it for the homeowner?
A higher tier costs more to build and tends to cut heating loads and bills over the life of the house, with comfort benefits such as steadier room temperatures. How the numbers balance depends on fuel prices, the climate and the builder, and quotes decide. The EnerGuide label described in our EnerGuide guide is one way to compare homes across tiers.
Drake Landing shows the logic at a small scale. Its 52 R-2000 homes cut space heating demand enough that a modest solar collector field could supply nearly all of it for years. The R-2000 homes guide and the DLSC homes page explain how.
Quick answers
What does Tier 5 mean in the National Building Code?
Tier 5 is the net-zero energy ready level for houses and small buildings. It describes a building efficient enough that on-site renewable energy could cover its annual energy needs, though the renewable equipment is not required.
Is net-zero energy ready the same as net zero?
No. Net-zero energy ready is an efficiency standard for the building. A true net zero building also has enough renewable generation to match its annual energy use.
Who decides which tier is required?
Each province or territory decides which code edition and tier are mandatory, and some municipalities encourage higher tiers voluntarily. Ask your building department what applies to your permit.
Do I need solar panels to meet a net-zero ready tier?
No. The tiers measure the efficiency of the building itself, so panels are not required. Many owners add solar later, and a ready house is built to make that easier.